A problem that occurs in the preparation of food in ovens is that, due to the heating of the preparation space, the outer side of the oven also heats up. This can result in danger to users and damage in the vicinity of the oven. This heating is a particular problem in the case of ovens which are used intensively, such as ovens in aircraft. In aircraft food has a major effect on the way in which a passenger perceives a journey. It is therefore of great importance for airlines to be able to provide all passengers with a meal on time during a flight. This involves ovens in aircraft having to have a high capacity and being capable of intensive use.
An additional problem with aircraft ovens is that they must satisfy diverse requirements in respect of safety, while the users also demand that these ovens take up the least possible space and weigh as little as possible, so that the unladen weight of the aircraft does not become too high. International standards and regulations, for instance the ARINC standard, apply in respect of the mounting and connection of ovens in aircraft. These lay down, among other requirements, the overall dimensions of ovens, as well as the maximum allowable temperature on the outside of an oven. Because space is scarce in aircraft, manufacturers strive to make the overall space for ovens and other equipment as small as possible. If the outer temperature of the oven is then relatively high, damage to the surrounding construction occurs quite quickly.
The invention now has for its object to solve this problem. This is achieved in a method as described in the preamble in that the outer side of the oven is cooled during the preparation. By cooling the outer side the temperature in the immediate vicinity of the oven can be limited without additional insulation material having to be arranged for this purpose around the preparation space. Such insulation material would after all make the oven heavier and take up space.
Cooling can be realized in simple manner when cooling air is forced along at least one outer surface of the oven. Air cooling does after all require fewer structural provisions than liquid cooling.
A very efficient cooling is obtained when the cooling air is also forced through the oven. Two functions, internal cooling and external cooling, can thus be combined with each other.
The cooling air is here advantageously forced along electronics in the oven. For cooling of the control electronics, which are usually situated above the hot preparation space, about the same amount of cooling air is required as for cooling the outer side of the oven.
Since the electronics require somewhat more cooling than the outer side, it is recommended that the cooling air is forced first through the oven and then along the at least one outer surface.
This can be realized in structurally simple manner when the cooling air is drawn in on the front side of the oven and blown out on the rear side, and the blown-out cooling air is guided along the at least one outer surface back to the front side.
The invention also relates to an oven with which the above described method can be applied. A conventional aircraft oven comprises a preparation space and means for heating the preparation space. An aircraft oven according to the invention is distinguished herefrom by means for cooling the outer side of the oven.
For the reasons stated above the cooling means can be adapted to force cooling air along at least one outer surface of the oven. In addition, the cooling means can be adapted to force the cooling air through the oven, in particular through or along an electronics compartment. The cooling means can further be adapted to force the cooling air first through the oven and then along the at least one outer surface.
In a preferred embodiment of the oven according to the invention the cooling means comprise at least one suction opening, at least one cooling fan arranged in the oven and at least one blow-out opening, and means arranged downstream of the blow-out opening for the purpose of guiding the blown-out cooling air along the at least one outer surface. The suction opening can here advantageously be formed in or close to the front side of the oven and the blow-out opening in or close to the rear side thereof, and the guide means can be adapted to guide the blown-out cooling air back along the outer surface to the front side.
A structurally simple embodiment of the oven is realized when the guide means comprise at least one channel running from the blow-out opening to a side part of the oven. The blown-out cooling air can be guided easily and with minimum flow losses through such a channel to the side of the oven for cooling.
The guide means preferably comprise two channels extending from the blow-out opening to both sides of the oven. The warmest part of the periphery of the oven can thus be cooled in its entirety. It must be taken into account here that the top side of the oven, which is separated from the preparation space by the cooled electronics compartment, becomes less warm.
In order to distribute the cooling air over the whole height of the side walls and moreover prevent it being blown out with too great a force on the front side adjacently of the oven, the or each channel preferably has a section increasing from the blow-out opening toward the side of the oven.
A structurally simple embodiment of the oven is realized when the or each channel is defined by a plate extending substantially parallel to the rear side of the oven and having a bent end part at the position of an edge between the rear side and the side part.
The invention will now be elucidated on the basis of an example, wherein reference is made to the accompanying drawing, in which: